Expansible piston



June 18, 193 c. s. JOHNSTON EXPANSIBLE PISTON Filed Nov 10, 1933 J ffy-a.

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awe/MM roN Patented June 18, 1935 UNITED- and has for its object the STATES PATENT "OFFICE r EXPANSIBLE rrs'ron Clarence S. Johnston, Amarillo, Tex. Application November 10, 1933, Serial No. esuss 4 Claims- (ci. 309-12) This invention relates to expansible pistons production of a sim-.

. ple and efiicient means for facilitating the exing of the piston after invention will ppear pansion of the piston and preventing the shrinkit has once been exthe invention is the production of a simple and eflicieht means for expending a piston consisting ot a plurality of diverging wedge-shaped pins which are so mounted as to facilitate the spreading or expansion of the piston skirt as the wedge-shaped pins are adjusted longitudinally.

A still further object of production of a simple and ture which is so assembled this invention is the eillcient piston strucas to provide means for preventing the cracking or splitting of the piston while it is being expanded.

This application is an improvement on my prior Patent #l,890,51l.

Other objects and advantages or the present throughout theiollowing specification and claims.

In the drawing:- Figure 1 is a side elevation of the piston;

Figure 2 is a section taken on line 2-2 of Figure 1;

Figure 3 ure 2;

is a section taken on line 3-3 of Fig- Figure 4 is 'a' fragmentary bottom plan view of a portion of the inner end of the piston;

Figure 5 is a vertical sectional view taken on line 5-5 of Figure Figure 6 is a side piston showing means elevation of a portion of the for facilitating the with! drawal of the expansion wedge pins;

Figure '7 is a perspective view plates adapted to be emreinforcing or hinge bedded or molded within and Figure 8 showing one of .the

threaded to provide a proper drawing,

which is provided with H being longitudinally split,

split longitudinally exupon the inner face-0t clearly in Figure 2. This I3 is provided with a wedge 'By referring to the III designates the piston a skirt II, the skirt as at l2, and having a tending boss l3 formed the skirt, as shown longitudinal split boss shaped socket ll. extending of, with which socket the v and skirt communicate. A wedge-shaped, is threaded.

threaded socket and a suitable wrench-receivor one of the the piston casting;

is a modified form of the invention diverging pins and sockets adjustment. it will be seen that longitudinally theresplit portion of theboss threaded pin I5, also within the internally .fpiston, as shown preferably cast integrally with the skirt H, and

the piston skirt, as well as these web portions ll, 10 is preferably formed of cast aluminum alloy as is common to the trade. These transversely extending web portions are provided with longitudinally extending expansion channels l8 which channels taper toward the upper end of the piston, and the channels are also diverged outwardly away from the central longitudinal axis of the in Figures 1 and 3. These expansion channels l8 are preferably circular in cross-section, and are provided upon diametrical- 20 iv opposite sides, running transversely of the web portions H, with relatively narrow expansion channels l9. In order to prevent the cast aluminum alloy web portions I! from splitting or breaking under expansion and contraction, I 5 cast longitudinally extending steel hinge plates 20 within the web portions H, as shown in Figure 2, and these hinge plates comprise substantially elongated-steel reinforcing members having bent longitudinally extending edge flanges 2i and a 30 rolled longitudinally extending centrally located head portion 22, the bead portion 22 of each hinge 20 being located in one of the diametrically opposite expansion channels I! and extending outwardly and beyond the cast web portion II. To 35 anchor the plates 20 firmly in position, a plurality of apertures 23 are formed therein to permit the cast aluminum alloy to extend through the apertures and form a firm anchoring means.

' These longitudinally extending. rolled or bead 40.

portions 22 will permit of a proper expansion and contraction throughout substantially the entire length of the web portions l1 under the expansion and contraction "of these web portions. The usual piston bosses are carried by the oppositely 46 arranged web portions II, as shown in the draw- I The tapering exp nsion channels I8 are adapted to receive the tapering pins 25 which pins are adapted to be driven into the expansion chan- 60 nels ill for the purpose of spreading the skirt H. The skirt II is split, as at 26, upon diametrically. opposite sides and in substantial alignment'with the central axis of the bosses 2|, the split portions 26 preferably extending atian angle to the piston, thereby v I as new is:

longitudinal aids of the piston, as shown in Figof the skirt, said web havingan expansion chanure 1. The expansion pins 25 may be provided nel, and a hinge member formed within the web with knobs 21 at their lower ends for facilitating nd an a d chann l f r r inf rcin the the operation of the pins, and in order to hold Same ns pllttin these pins 25 against accidental displacement, a In combination with a P s avin a sp i 5 11 1; ki Spring 13 is employed f r each set f skirt, an integral web formed upon the inner walls pins upon opposite sides of t pjston These of the skirt, said web having an expansion chansprings 28 are anchored within a boss 29 mounted 1191, and 8815681 hinge molded l n dinally Wi hin upon ach id of th pistgn below t piston said web and spanning said channel for reinforcbosses 24. Thi structure i Shown Figures ing the web and preventing the splitting thereof 4 and 5. The ends of the spring 28 are preferably h the Skirt is p nd denlarged as indicated at 30, and suitable aper- In combination With a piston v n a pl t tures 3| are formed in these enlarged portions 30 skirt, a web formed integrally with the skirt and to fit over the lmobs 21 of the ins 25 to hold the n n t s irt, aid web hav n a l neitudipins in position. nally extending expansion channel, a reinforcing The lower ends of the tapering expansion pins member p s g a r at ve y flat P a e c s may be threaded, as at 32, for receiving within said web portion and provided with a latnut 33 which may be used to abut against th erally extending longitudinally formed rolled bead lower edge oi. the web portions I! to facilitate t ndin l ntward y of t w and spanni the drawing of the piston pins 25 outwardly for said channel to provide a hinge, and expansion 2 adjustment or removal of the pins. means aifiustably mounted within the expansion As shown in Figure 8, the expansion channel h nnel- Ila may be internally threaded for receiving the n C mb na i n W th a Piston having a Sp t externally threaded expansion pin 25a and this skirt, a web formed integrally with the skirt and expansion pin 25a may be provided with hex- Sp n n e S a Web having a longitlldlagonal, square, or other wrench-receiving knob nally'extending expansion channel, a reinforcing 21a and a suitable locking spring 28a suitably member comprising a relatively fiat plate cast apertured may be employed for fitting over the within said web portion and provided with a letknob 26a to hold the pin 25a in position. This ally xt ndi n tudin y f rm d rolled pin 25aissimilar to the pin-25 previously described b ad extendin outward y of the web a d spanwith the exception of the threading of the pin and fling Said h n l t P v de a h n xp n i n channel. means adJustably mounted within the expansion Having described the invention, what is claimed channel. d t hinge having turned edges to facilitate the anchoring of the hinge in said cast- 1. In combination-with a piston having a split skirt, an integral web formed upon the inner walls CLARENCE S. JOHNSTON. 

